1. Technical Field
The present invention relates to a pressure container for filling pressurized substances.
2. Related Art
For example, Japanese Unexamined Patent Publication No. 2000-291888 and Japanese Unexamined Patent Publication No. 2014-167346 disclose a pressure container for filling compressed gas such as hydrogen and compressed natural gas (CNG). Japanese Unexamined Patent Publication No. 2000-291888 discloses the pressure container in which a metal mouthpiece is integrally attached to an opening circumferential edge of a cylindrical resin liner, and a surface of the liner is covered with a reinforcing layer. The mouthpiece includes a boss portion having a cylindrical shape, and a flange portion which protrudes toward a radially outer side from the boss portion. According to Japanese Unexamined Patent Publication No. 2000-291888, an annular groove is provided at a bottom portion of the flange portion, and one part of the liner is fitted into the annular groove, thus enhancing sealability between the mouthpiece and the liner.
Meanwhile, Japanese Unexamined Patent Publication No. 2014-167346 discloses the pressure container in which a groove portion is provided at a bottom portion of a flange portion of a mouthpiece, an opening end of the liner, a collar member, and a seal member of an elastic body are disposed in the groove portion, and the opening end of the liner is sandwiched between a groove portion wall surface, the collar member, and the seal member, thus enhancing the sealability between the mouthpiece and the liner.
However, in Japanese Unexamined Patent Publication No. 2000-291888, one part of the liner is slidably disposed in the annular groove to alleviate stress concentration at the time of expansion or contraction of the liner. Since the one part of the liner moves within the annular groove, the sealability between the liner and the annular groove wall surface is insufficient.
In Japanese Unexamined Patent Publication No. 2014-167346, in the groove portion of the flange portion of the mouthpiece, the opening end of the liner is fixed to the groove portion by being sandwiched between the collar member and the seal member. The occurrence of stress concentration at the opening end of the liner by the expansion or contraction of the liner becomes a concern. Furthermore, since the collar member and the seal member need to be attached to the inside of the groove portion, the number of components increases and the attachment is troublesome.